As a result of an analytical investigation on Bulgarian rose oil (Rosa Damascena Mill.), E. sz. Kovats could determine for the first time the presence therein of a furan derivative of formula ##STR1## 3-methyl-2-[3-methyl-but-2-en-1-yl]-furan, known ever since under the name of "rosefuran". The first total synthesis of this compound was realized by G. Buchi et al. [see: J. Org. Chem., 33, 1227(1968)] by making use of 3-methyl-2-furoic acid according to the hereinbelow illustrated process: ##STR2## More recently [see: O. P. Vig et al., J. Indian Chem.Soc., 51, (10), 900-2 (1974)], rosefuran has been synthesized starting from 3-furylmethanol according to the following reaction scheme: ##STR3##
Though interesting they may be from the academic viewpoint, the two above mentioned processes are particularly unsatisfactory whenever applied to the industrial large scale preparation of rosefuran, their main disadvantage being represented by the high price of the required starting materials.
In view of the usefulness presented by rosefuran, the perfume industry has constantly shown a lively interest to its synthesis; sofar however without any success.